Magneto generator



March 22, 1938. T. TOGNOLA MAGNETO GENERATOR Filed Sept. 24, 1936 3 Sheets-Sheet l I iiixlilim INVENTOR.

TORNEY.

March 22, 1938. 1 -r TOGNQLA 2,112,214

MAGNETO GENERATOR Filed Sept. 24, 1936 5 Sheets-Sheet 2 QQ." "F. 33 30 16 52 y C C INVENTOR.

' W TORNEY.

March 22, 1938. T. TOGNOLA 2,112,214-

MAGNETO GENERATOR Fi led Sept. 24, 1936 s Sheets-Sheet z IN VEN TOR.

wanes/9 BY Ww 709n06w A ORNEY.

V Patented Mar. 22, 1938 UNITED STATES PATENT OFFICE MAGNETO Tullio Tognola, Sidney,

GENERATOR N. Y.; assignor to Bendix Aviation Corporation, South Bend, Ind., a corporation of Delaware 4 Claims.

The present invention relates to magneto generators for ignition systems of internal combustion engines and more particularly to a novel form of breaker mechanism therefor.

One of the most important factors which limit the periods of. continuous operation of commercial types of ignition magnetos is the breaker mechanism including the electrical contacts and the cam operating mechanism therefor. contact points, even though made of refractory and non-corrosive metal, gradually oxidize and pit, and the cam mechanism is subject to wear whereby the adjustment and efficiency of the breaker mechanism is affected.

It is an object of the present invention to provide a novel breaker mechanism for magneto generators in which oxidation of the contact points and wear of the operating mechanism are substantially prevented.

It is another object to provide such a device in which the contact points are enclosed in an inert atmosphere. I

It is a further object to provide such a device in which the contact assembly is in the form of a capsule which is readily replaceable as a unit.

It is another object to provide such a device in which the contacts may be observed and adjusted without opening the capsule. p

It is another object to provide such a device in which the contacts are operated magnetically, without any moving elements subject to frictional wean.

Further objects and advantages will be apparent from the following description taken in connection with the accompanying drawings in which: n a

Fig. 1 is an end view of a magneto incorporating one preferred embodiment of the present invention,-the cover of the breaker mechanism being removed, and the breaker mechanism being shown substantially in vertical section;

Fig. 2 is a sectional view of a magneto embodying a second preferred form of the present invention; 4

Fig. 3 is a side elevation of the magneto illustrated in Fig. 2, parts being broken away and shown in section for the sake of clarity; and

Fig. 4 is a detail in perspective of one form of adjusting means to vary the timing of the breaker mechanism.

Referring first to Fig. 1 of the drawings, there is illustrated a magneto indicated generally by thenumeral I having a rotor shaft 2 on which is fixedly mounted in any suitable manner a permanent magnet structure here shown in the form of a cross 3 magnetized with subsequent-poles of unlike polarity as indicated by the letters N, S. A breaker cup 4 is rotatably mounted on the end of the magneto casing as by means of arcuate slots 5 in the cup and retaining studs 6 threaded into the magneto casing.

According to the present invention, breaker mechanism for the primary circuit of the magneto is provided in the form of a movable contact I mounted on a spring 8 anchored to an insulated binding post 9 which is connected by means of a lead II to the primary winding of the magneto induction coil, notillustrated. An adjustable stationary contact I2 is arranged to cooperate with the movable contact 1 and, as here shown, is mounted on the end of a stud l3 which is threaded into a metallic casing M. The casing M is closed at its ends by means of caps l5 and IS, the cap I5 being arranged to retain the insulated binding post 9, and the cap it being preferably arranged to hold a sealing member I! of suitable transparent material permitting observation of the breaker points I and 12.

The casing l4 and caps l5, l6 form an airtight capsule which is adapted to be evacuated or filled with an inert gas through an opening I8 which is subsequently sealed in order that the contacts may be maintained in an inert atmosphere. The capsule l4, l5, i6 is removably retained in position and grounded to the magneto frame by suitable clamping means such as the brackets l9 and 2| which are suitably fixed to mounting members 22 and 23 which are fixedly attached to the breaker cup 4 in any suitable manner.

The casing I4 and the brackets l9 and 2| are of non-magnetic material, but the mounting members 22 and 23 are made of readily permeable I material and are formed as pole pieces adapted to cooperate with the poles of the magnet 3 and having projections 24 and 25 extending into close proximity to the casing I4. An armature 26 of readily permeable material is attached in any suitable way to the spring 8 carrying the movable contact I and is located closely adjacent to the interior wall of the casing M which may be flattened as indicated at 21 in order to reduce the gaps between the projections 24, 25 of the pole pieces and the ends of the armature 26.

In order to prevent grounding the contact l when the armature is attracted by the magnetic pole pieces, a buffer element 28 of suitable insulating material is mounted in the casing H in position to limit the travel of the contact I away from the fixed contact [2.

In the operation of this embodiment of the invention, the capsule containing the breaker mechanism is mounted in the brackets [9, 2|, as illustrated, with the armature 26 adjacent the pole pieces 22, 23, the rotor is turned until a pair of poles of the magnet 3 are in operative relation to the pole pieces, as illustrated, and the contact I2 is adjusted into proper spaced relation with the contact 1. The magneto is then timed in the usual manner and the breaker cup 4 rotated by means of the operating arm 29 to such angular position that the magnet attracts the armature 26 and causes, the contacts I, I2 to openin the proper timed relation with the operation of the engine to be ignited. Thereafter, rotation of the magnet 3 with the magneto rotor causes the contact I to be vibrated to open and close the primary circuit of the magneto in the usual manner.

Inasmuch as the contacts 1 and I2 are not subject to ,any oxidizing action, and the operating mechanism therefor involves no moving parts subject to friction, it is obvious that this arrangement is peculiarly Well adapted for reliable operation over long periods of time. If, however, it should become necessary to replace the breaker mechanism, it will be obvious that this is very readily brought about by merely loosening one of the brackets l9 or 2|, removing the lead II, and replacing the capsule as a unit with a new breaker capsule.

In the embodiment of the invention illustrated in Figs. 2 and 3, the magnetic elements of the magneto rotor are used to operate the breaker mechanism without the necessity of an additional magnet for that purpose. As best shown in Fig. 2, the breaker capsule indicated generally by the numeral 30is removably mounted on the frame 3| of the magneto by means of clamps 32 and 33 fixed thereto as by means of studs 34 and 35. The elements of the breaker mechanism are the same as previously described in connection with Fig. l and are similarly numbered.

As shown in Figs. 3 and 2, the breaker mechanism is located on the frame of the magneto in the same plane as the stationary pole pieces 35 and 31 which conduct the flux from the elements 38, 39, 40, 4| of the multi-polar magnetic inductor rotor 42 through the core of an induction coil 43 of the usual type. Auxiliary pole pieces 44 and 45 are provided for conducting the flux from these same rotor magnetic elements to actuate the armature 26 of the breaker mechanism, those magnetic elements of the rotor being utilized for that purpose which are not at that time operative with respect to the induction c011.

Means are preferably provided for adjusting the angular position of the rotor at which the magnetic elements thereof are efi'ective on the armature 26 to open contacts I, I2. As here shown, this means is in the form of a pair of arcuate shoes 46 and 41 of permeable material mounted on the pole pieces .44 and 45 adjacent the path of the magnetic elements of the rotor 42, these shoes being preferably connected by an arcuate strip of non-magnetic material 48 (Fig. 4) and actuated by any suitable means such as a manually operable arm 49.

In the operation of this embodiment of the invention, rotation of the magnetic elements of the inductor rotor 42 causes said elements to impress the magnetic fiux thereof alternately in opposite directions through the magnetic circuit of the induction coil 43 in the usual manner. At the same time, said elements which are idle with respect to the induction coil, are effective to cause magnetic flux to periodically traverse the pole pieces 44 and 45 and the armature 26 so as to attract the armature and open contacts I, I2, thus breaking the primary circuit of the induction coil. It will be understood that the slidable shoes 46, 41 are so adjusted that the flux of the rotor magnets is eifective to open said contacts in the proper timed relation to the rotation of the rotor.

Although certain forms of the invention have been shown and described in detail, it will be understood that other forms are possible and that various changes may be made in the design and arrangements of the parts without departing from the spirit of the invention as defined in the claims appended hereto.

What is claimed is:

1. In a magneto generator a rotor, a magnet rotatable thereby, breaker mechanism, a capsule enclosing the breaker mechanism in an inert atmosphere, an armature within the capsule arranged to actuate the breaker mechanism, means forming a magnetic circuit including said magnet and armature, and means for angularly adlusting the operative relationship of the magnet and armature.

2. In a magneto generator a rotor, a magnet rotatable thereby, breaker mechanism, a capsule enclosing the breaker mechanism in an inert atmosphere, an armature within the capsule arranged to actuate the breaker mechanism, means forming a magnetic circuit including said magnet and armature, and means operable outside the capsule for adjusting said breaker mechanism, said capsule having a transparent wall permitting observation of the breaker mechanism.

3. In a high tension magneto a rotor including a multi-polar magnetic inductor, an induction coil having primary and secondary windings, means for conducting flux from said inductor through said coil, breaker mechanism in circuit with said primary winding for periodically interrupting the flow of current therein, a nonmagnetic sheath hermetically enclosing said breaker mechanism in an inert atmosphere. means including an armature within the sheath for actuating said breaker mechanism, means including pole shoes adjacent the path of the poles of said inductor arranged to conduct flux from said poles through said armature, and means for angularly adjusting the operative relation of the poles of the inductor with respect to said armature.

4. In a magneto generator, a magnetic rotor, a coil, breaker mechanism for said coil including a sealed tubular capsule containing in an inert atmosphere an insulated movable contact and a grounded fixed contact, means for operating the movable contact including an actuating element in the form of an armature connected thereto, and removable brackets for detachably mounting the capsule with its armature in inductive relation with the rotor.

TULLIO TOGNQLA. 

